Foreign Secretary Albert del Rosario said The Philippines would strongly support a rearmed Japan - its World War II foe - as a counterweight to what it sees as Chinese provocation.

"We are looking for balancing factors in the region and Japan could be a significant balancing factor," he told the Financial Times, amid growing tensions over the South China Sea, almost all of which is claimed by China.

Department of Foreign Affairs spokesman Raul Hernandez confirmed the government's view that Japan should upgrade its military from a self-defence force so that it has more freedom to operate in the region. "(Mr Del Rosario) said we are in favour of Japan's gaining strength," Mr Hernandez said later.